1. Field of the Invention
This invention concerns apparatus for jacking and dollying a vehicle wheel assembly while the assembly remains affixed to the vehicle; and more particularly, a jacking and dollying apparatus for use with a wheel assembly including a pneumatic tire, wheel and axle, the apparatus including wheel engaging means and an actuator; as for example, an adjustable roller assembly and a lever mechanism which cooperate to facilitate the lifting and conveying of the wheel assembly while it is affixed, and whether the pneumatic tire is inflated or deflated.
2. Description of Related Art
Movement of conventional vehicles in a confined spaces is difficult and inefficient at best, and can be impossible altogether. Because most cars and trucks are equipped with front wheel steering, a series of repeated backward and forward maneuvers is required to locate them in limited spaces, such as those found in repair garages or body shops. Further, on those occasions when size and geometry of the space is particularly limited, it may be impossible to position the vehicle as desired at all.
This problem arises from the inherent limitations associated with front wheel steering. As all drivers have found, front wheel steering, permits vehicle movement in only straight line and relatively broad arcuate paths. As a result, where right angle, rotational or shallow arcuate paths are desired, movement may not be possible unless sufficient space is provided to approximate those paths with a series of straight line and broad arc maneuvers.
Such space requirements can, however, be a luxury. In the case of a garage or body shop, providing sufficient space to accommodate front wheel steering may require servicing fewer vehicles, making the facility; i.e., floor space, larger, or some combination of the two. But, both accommodating fewer vehicles and providing larger space are costly. They entail either loss of operating revenue due to the reduced number of vehicles served, or additional capital outlay for construction of increased space.
The movement shortcomings associated with front wheel steering arise from the rstricted turning ability the vehicle wheels are provided with. Particularly, the vehicle front wheels are constrained to turn together, and only through a limited angle, while the back wheels can not be turned at all. However, if each of the vehicle wheels were free to swivel 360 degrees about its vertical axis; e.g., like a dolly caster, vehicle movement limitations would be eliminated. In fact, if the vehicle were placed on a dolly, the independent 360 degree swivel action afforded by the dolly casters would permit the vehicle to be moved at right angles, rotationally or through shallow arcuate paths as desired.
The complexity of providing a suitable dolly, and the loading and unloading of a vehicle to and from it, however, is not insignificant. To be successful, the dolly would have to have a capacity sufficient to sustain the vehicle's size and weight, and, as a result, would require costly and bulky construction. Further, means would have to be provided for getting the vehicle from the ground onto the dolly, and from the dolly back to the ground again. As can be imagined, where a hoist was used, it too would not be insignificant in size and cost.
An alternative to lifting the entire vehicle onto a single dolly would be to use individual jacking and dolly units placed at each vehicle wheel assembly. Use of individual units capable of both lifting the wheel assembly and carrying it, while affixed, would permit the wheel assembly to be raised from the ground, and once raised, effectively swiveled through 360 degrees by means of casters provided on the unit. With the wheel assembly so mounted, the vehicle could be moved at right angles, rotationally of through shallow arcuate paths as desired.
Further, use of individual units could provide substantial cost savings. The work required of individual units would be significantly less than that of a single large dolly. With individual units, only approximately a quarter of the vehicle's weight would have to be sustained, and none of its size; i.e., spanning between wheels would be eliminated. Accordingly, the bulk, complexity and cost of individual dolly units would be substantially less than that of a single dolly. Further, the need for a complex and costly vehicle hoist or jack would be eliminated.
But even in the case of individual units problems remain. In particular, if an individual unit is to be effective, not only should it combine, in a single apparatus, the ability to both lift the wheel assembly from the ground and, thereafter, transport it, but also, it should be flexible enough to accomodate the wide variety of vehicle wheel assembly sizes commonly found today. Further, because it is not uncommon for the tire of a wheel assembly to be flat, particularly in a garage or body shop, the unit must be able to lift the wheel assembly whether the tire is inflated or deflated. Still further, to be commercially attractive, the unit should be simply and quickly manipulated by a single operator. Further still, these results must be achieved with a structure whose bulk does not interfere with vehicle movement or whoes cost does not prohibit use.
While dollies have been proposed for removing a vehicle tire and wheel, and transporting them once removed, none have been proposed for the more difficult task of jacking and dollying the vehicle wheel assembly; i.e., jacking and dollying the combined tire, wheel and axle, while they remain affixed. In operation, tire and wheel dollies are used in conjunction with a separate jack. The separate jack is required to lift the vehicle axle so that the dolly may be positioned beneath the tire and wheel. But, use of a separate jack is unattractive because of the extra time and cost associated with it.
What jacking capacity these dollies do have is addressed to lifting the tire and wheel from the vehicle. They do not include means intended to lift the entire wheel assembly; i.e., tire, wheel and axle while affixed. Nor are they capable, typically, of lifting a deflated tire before it is raised from the ground by the separate jack. Additionally, these dollies tend to have awkward and slow acting mechanisms which don't lend themselves to quick, single motion manipulation by a operator. Further, typically, they have a size and configuration that would encumber movement of the vehicle once it was lifted.
For example, E. R. Carruthers in U.S. Pat. No. 2,380,415, issued Jul. 31, 1945, proposes a tire and wheel dolly suitable for handling truck dual rear whee. In accordance with the Carruthers design, a separate jack is needed to lift the truck axle, wheel and tires from the ground so that his apparatus can be rolled beneath. Thereafter, cradles provided on the apparatus are brought beneath and against the tires by means of a crank and screw mechanism to lift the tires and wheels from the axle. Accordingly, the Carruthers apparatus requires the undesirable step and equipment for separately lifting the wheel assembly before the apparaus can be used. Additionally, because of its design, the Carruthers apparatus would not be suitable for lifting deflated tires, the action and range of motion of the cradles being dissipated in deforming the deflated tire. Further, the Carruthers design is not susceptible of quick, single action manipulation.
Another proposed tire and wheel dolly is described by W. F. Gemmill in his U.S. Pat. No. 2,217,898, issued Oct. 15, 1940. Like the Carruthers apparatus, the Gemmill dolly also requires a separate jack for initially lifting a truck axle, wheels and tires. Once the wheel assembly has been raised, arms on the apparatus may be caused to engage the truck tires to lift them together with their wheels from the truck's axle. Accordingly, as in the case of Carruthers design, the Gemmill dolly requires the use of a separate jack with its associated shortcomings. Further, due to the nature of its jacking arrangement, the Gemmill apparatus has an especially bulky and complex mechanism, and would, therefore, not be suited for unencumbered movement of the vehicle or quick action.
Other and similar examples of tire and wheel dollies are found in U.S. Pat. Nos. 1,967,119; 2,170,607; 2,386,516; 2,410,902 and 3,836,027. However, as in the case of the Carruthers and Gemmill dollies, separate jacks are relied upon to lift the vehicle axle. Additionally, the bulk, complexity and nature of operation of these dollies would encumber vehicle movement and not be suited for simple and quick operation.
A jack has, however, been proposed by R. L. Foringer in U.S. Pat. No. 2,332,443 issued Oct. 19, 1943, which is capable of lifting and dollying circular bodies. But, the Foringer jack, as described, is designed for lifting rigid objects such as large metal tanks. The jack features rollers mounted on arms, the arms being coupled by a threaded shaft and nut assembly. By manipulating a pawl and handle which extends from the device, the nut assembly draws the arms and associated rollers against the tank side walls causing the tank to lift. While the Foringer jack would appear capable of lifting an inflated tire, it, however, would not be capable of lifting a deflated tire; the action of drawing the rollers against the tread being dissipated in the deformation of the deflated tire. Further, the pawl and handle arrangement are unsuited for providing quick, single action operation, and would encumbered movement of the vehicle.